Ink cups (also known as but not limited to reservoirs, chambers, vessels, cartridges ink wells, etc.) are used in pad printing and other applications to bring ink to the printing plate surface and the artwork image area. The ink cup moves, open side down, on the printing plate surface, distributing ink via convection to the image area. The liquid ink inside the cup is mixed with a volatile solvent, which evaporates at a predictable rate of speed.
In the present technology, the ink cup is a single chamber filled with ink. As the cup moves across the printing plate, convection forces fresh ink from the interior of the cup towards the opening over the plate surface, pushing older ink back up the cup, exposing all solvent dissolved ink to the print plate surface and thereby to the air, leading to maximum evaporation of solvent and requiring that the ink cup be frequently re-filled with ink solvent mixture.
The present technology increases the viscosity of the entire ink supply while the ink cup moves over the print plate. The ink quickly becomes too thick to print effectively and must be adjusted at short intervals.
A method of reducing the exposure of all the ink to the air and plate surface as it is being used is needed to minimize refilling of the ink cup and limit evaporation of high-Volatile Organic Compound (VOC) solvents to the air. The prior art reveals a collection of print cup technologies that do not address these requirements.